The field of this invention relates to inflatable tire supporting structures and more particularly to an improved apparatus and method of manufacture of connecting the central spider of the wheel to the tire supporting rim.
It has been common practice for a great number of years to mount the inflatable tire upon a steel rim and then to secure the steel rim to the wheel drum of an automobile. Normally, such steel rims were formed as an integral unit in a rough cast form. In an effort to improve the appearance of the spider section of the wheel, which is centrally located with respect to the rim, it has been common to employ the use of a hub cap which is designed to be ornamental and pleasing to the eye. A large number of different types of hub caps of various designs have been employed.
Within the past few years it has been common to make ornamental the spider portion of the wheel itself thereby eliminating the need for a hub cap. It has been found that if the spider portion is formed of a nonferrous metal such as aluminum or magnesium, the spider is more respective to styling as by chrome plating than a steel spider. However, it has not been particularly easy to establish a strong, leakage free connection between the non-ferrous spider and the ferrous rim.
Most such rims are to support a tubeless tire wherein the rim must establish an airtight connection with the tire. It has been common practice in the past to rivet the rim to the spider. However, riveting inherently produces an aperture through the rim into the spider. As a result, it has been common that a non-perfect rivet connection causes the pressurized air within the tire to leak out past the rivet. Also, although a satisfactory rivet connection is initially established, after a period of time the rivet may loosen permitting the pressurized air to leak from the tire.
In an effort to overcome the use of rivets there have been numerous attempts at welding the spider to the rim. However, the welding of a non-ferrous metal to a ferrous metal is not easily accomplished even by the most skilled artisan. Further, the welding technique is inherently time consuming. The cost of manufacture of such wheel assemblies is substantially increased when using the welding technique.
It would be desirable to design a way of securing a non-ferrous spider to a ferrous rim without employing the use of welding or riveting techniques. It is desirable that the connection of the spider to the rim be extremely high strength and also absolutely preclude any leakage of air from the tire. Further, such a connection should be established quite economically and within a minimum amount of time, thereby lowering the manufacturing cost.